JPH0329116Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a robot hand for transporting articles having a functional surface portion and a non-functional margin portion on the upper surface.

[Prior Art] Various types of article gripping devices for gripping and conveying articles have been known as shown below.

(i) Attach the article using suction power such as vacuum suction.
2. Description of the Related Art There are known article gripping devices that use a so-called suction operation to grip an article and transport the gripped article from a predetermined position to another position or to attach it to another article. As a document disclosing such an article gripping device,
Utility Model Publication No. 54-6949, JP-A-55-150989, JP-A-61-35089, JP-A-62-18317
Publications, etc. exist. These publications disclose an article gripping device that directly sucks and holds an article.

(ii) An article gripping device is also known that employs a gripping method in which an article is gripped by a plurality of gripping members and finger members. For example, Japanese Utility Model Publication No. 56-6315 discloses a device in which three claw bodies are connected to a motor through a screw shaft and a bevel gear coupling means, and the motor opens and closes the claw bodies to grip an article. is disclosed. Japanese Patent Publication No. 58-50835 also discloses a device in which three finger members are driven by a motor via gears.

(iii) One of the functions of the gripping device of the present invention is a function of centering the object to be gripped. As an article gripping device equipped with such a centering function,
Publication No. 256004 is known.

(iv) Furthermore, in the prior art, Japanese Patent Laid-Open No. 14500/1983 is known as a mounting head equipped with a suction nozzle and a position regulating claw for regulating the position of an article.

[Problems to be solved by the invention] As mentioned above, this invention has the following problems in particular:
The present invention relates to an article gripping device suitable only for gripping optical lenses used in optical instruments, etc.
The lens surface of such an optical lens is required to have high precision surface finish and cleanliness in order to transmit and refract a light beam. As a result, when such an optical lens is incorporated into a lens barrel or optical device, it is absolutely not allowed to directly touch the optical functional surface and damage or stain it when gripping the optical lens. It is something.

For this reason, when assembling an optical lens into a lens barrel, it becomes impossible to grasp the outer peripheral portion of the optical lens from the outside with finger members and fit it into the lens barrel. That is, the inner peripheral surface of the lens barrel and the outer peripheral surface of the optical lens are set to have substantially the same dimensions. Therefore, there is no allowance for gripping the outer periphery of the optical lens from the outside with the finger members, and as a result, the optical lens is inserted into a predetermined position within the lens barrel while the optical lens is gripped. It becomes impossible.

Further, after the optical lens is fitted into the lens sealing portion inside the lens barrel, a metal elastic ring or C ring for fixing the optical lens must be inserted into the lens barrel. here,
The gripping device used to insert these rings into the lens barrel grips the ring from the outside in the radial direction with a plurality of finger members, and the distance between these finger members is set at a distance that is slightly larger than the outer diameter of the ring in its natural state. The ring is pressed inward in the radial direction so as to be compressed by a certain amount, and while the ring is held in this manner, the ring is inserted into the lens barrel into which the optical lens is fitted.
Here, in this gripping device, since a pressing force is applied to the ring by the finger members, it becomes difficult to remove the ring from the gripping device. As described above, if the ring cannot be removed smoothly from the gripping device, the lens cannot be reliably fixed by the ring, which is a problem.

This invention was made in view of the above-mentioned problems, and the purpose of this invention is to center the item and reliably attract it while storing it freely without making direct contact with the functional surface of the item. To provide a robot hand that can be transported.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the purpose, the robot hand according to this invention includes an article having a functional surface portion and a non-functional margin portion on the upper surface. A robot hand for transport includes a hand main body that is movable vertically and laterally, and an outer surface that is attached to the hand main body and aligned vertically with the outer periphery of the object to be transferred. and a plurality of regulating pieces that abut the margin portion of the article from above; and a plurality of regulating pieces that are attached to the hand main body, and in a state that the regulating pieces abut the margin portion of the article from above, a predetermined interval approximately at the center of the article. a suction member that is lowered to above the hand body, a centering position where the suction member contacts the outer surface of the hand body on the outside of the corresponding restriction piece, and a standby position that is spaced radially outward from this. It is characterized by comprising a plurality of centering members rotatably attached between the centering members.

[Function] In the robot hand configured as described above, first, the regulating piece is set upward on the margin of the article so that the outer surface of the regulating piece and the outer periphery of the article are vertically aligned. Ru. From this state, the regulating piece approaches the margin portion of the article from above. In this close state, the centering member rotates from the standby position to the centering position to set the article so that its center position is aligned with the center position of the hand body. Thereafter, the suction member is lowered to above the approximate center of the article to suction the article. In this way, the article comes into contact with the lifted regulation piece from below and is eventually attracted to the robot hand. In this way, the article is attracted to the robot hand and is freely transferred as the robot hand moves.

[Embodiment] Below, the configuration of an embodiment of the robot hand according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, this robot hand 10
is attached to the lower end of a robot arm (not shown) so that it can be replaced depending on the type of article to be sucked, and in this embodiment, a lens 12 of an optical system is sucked and transferred as the article. It is provided for. Here, this optical lens 12
is defined as an optically functional surface whose central part is precisely polished, and the outer periphery other than this optically functional surface is defined as a margin part, which has no function related to the optical system. .

This robot hand 10, as shown in the figure,
A hand body 14 is provided which is detachably attached to the lower end of the robot arm. This hand body 14
is formed into a hollow cylindrical shape with both upper and lower ends open, extending along the vertical direction, and has a spur gear 16 coaxially attached to the upper end thereof, and a spur gear 16 coaxially attached to the lower end thereof. Bevel gears 18 are each rotatably attached to the hand body 14. Further, a long groove 20 is formed in the peripheral wall of the hand main body 14 so as to extend in the vertical direction.

On the other hand, a through hole is formed in the center of the above-mentioned spur gear 16, and a female thread groove (not shown) is threaded on the inner peripheral surface of the through hole. A suction tube 24 serving as a suction member is attached to the hand body 14 so as to protrude vertically within the hand body 14, with a male screw portion 22 that is screwed into the female screw groove integrally provided at the upper portion. The circumferential wall of this suction tube 24 has the long groove 2 described above.
An engagement pin 26 that is inserted through the hole is integrally formed and projects radially outward. With this configuration of the suction tube 24, the spur gear 16 is rotationally driven, and the suction tube 24 is connected to the hand body 14 through the engagement between the engagement pin 26 and the long groove 20.
It will move up and down inside.

Note that the upper end of this suction tube 24 is connected to a suction pump 30 via a tube 28. In this manner, in response to the suction pump 30 being activated, the lower end opening of the suction tube 24 performs a suction operation, thereby suctioning the articles in the vicinity thereof with negative pressure.

On the other hand, three angle members 32, 34, and 36 are integrally attached to the outer circumferential surface of the upper part of the hand main body 14 so as to face outward in the radial direction. These angle members 32, 34, 36 are arranged at equal intervals along the circumferential direction, and have bent pieces 38, 40, 4 bent downward at their tips.
2 are integrally formed. Each bent piece 38, 4
A pair of guide rods 44a, 44b, 46a, 46 extend along the radial direction and are vertically spaced apart between the guide rods 44a, 42 and the hand body 14.
b, 48a, and 48b are bridged over each other.

In addition, each angle member 32, 34, 36 includes
Corresponding guide rods 44a, 44b, 46a,
In the state located between 46b, 48a, 48b,
Threaded rods 50, 52, 5 extend along the radial direction.
4 are arranged. Each threaded rod 50, 52, 54
The outer ends of the corresponding bent pieces 38, 40, 42
Small bevel gears 56, 58, and 60 that mesh with the aforementioned bevel gear 18 are coaxially and integrally attached to the inner end thereof. Note that the small bevel gear 60 is hidden behind the hand main body 14 and is not shown in FIG.

Here, each angle member 32, 34, 36 has a corresponding guide rod 44a, 44b, 46.
Slide blocks 62, 64, and 66 are disposed by a, 46b, 48a, and 48b to be slidable along the radial direction of the hand body 14, respectively. Each slide block 62, 64, 66 is screwed into the corresponding threaded rod 50, 52, 54, respectively, and in this way, when the bevel gear 18 is rotationally driven, the threaded rod 50, 52, 54 is rotated. Depending on the rotation, these slide blocks 62, 64, 66
will slide simultaneously along the radial direction.

The slide block 62 configured in this way,
Regulating pieces 68, 70, 72 as finger members are fixed to the lower surfaces of the fingers 64, 66, respectively, in a vertically falling state. These regulating pieces 68, 70,
72 is arranged around the hand main body 14 so as to be coaxial therewith. Further, the lower ends of these regulating pieces 68, 70, and 72 are set at the same height, and are adapted to abut from above a margin defined on the outer periphery of the upper surface of the optical lens 12 as an article. .

On the other hand, a first drive motor 74 for vertically moving the suction tube 24 is attached to the upper surface of the first angle member 32 via an attachment stay 76. The first drive motor 74 has a drive shaft 74a projecting downward, and a drive spur gear 78 that meshes with the spur gear 16 described above is coaxially attached to the drive shaft 74a so as to rotate integrally with the drive shaft 74a. Fixed.

Moreover, slide blocks 62, 64, 66 are provided on the outer surface of the bending piece 42 of the third angle member 36.
A second drive motor 80 is mounted for sliding the radially. The drive motor 80 includes a drive shaft extending in the radial direction, and the drive shaft is connected to the threaded rod 54 so as to rotate together with the threaded rod 54 in alignment.

Here, each slide block 62, 6 mentioned above
The lower surface of 4, 66 is provided to accurately position the optical lens 12 with respect to the robot hand 10, prior to the suction operation of the optical lens 12.
a centering member 82 for centering;
84 and 86 are provided, respectively.

Each centering member 82, 84, 86 is attached to the upper end of the corresponding regulating piece 68, 70, 72 and to the attachment portion of the corresponding slide block 62, 64, 66 via a pivot pin 88, respectively. The slide blocks 62, 64, and 66 are rotatably supported in a vertical plane passing through the sliding loci of the slide blocks 62, 64, and 66. That is, each centering member 82, 84, 86 has a corresponding regulating piece 68, as shown by a solid line in FIG.
A standby position spaced outward by a predetermined angle from 70 and 72 and a corresponding regulating piece 6 as shown by the broken line.
8, 70, and 72, and are rotatably supported between the centering position and the centering position in contact with the outer side surfaces of the members 8, 70, and 72.

In addition, each centering member 82, 84, 86 is
They are formed to extend slightly downward from the lower ends of the corresponding regulating pieces 68, 70, 72.

Here, each centering member 82, 84, 86
Air cylinder mechanisms 90, 92, 9 are used to rotate between the standby position and the centering position.
4 are connected to each other. Each air cylinder mechanism 90, 92, 94 is connected to the corresponding centering member 82, 84, 86 via a pivot pin 96 at the rear end of the corresponding slide block 62, 64, 66.
a mounting piece 98 rotatably supported in the same plane as the mounting piece 98;
100, 102 and corresponding mounting pieces 98, 10
Cylinder body 10 attached to 0,102
4, 106, 108 and each cylinder body 104,
Pistons 11 are provided at 106 and 108 so as to be able to protrude and retract according to air pressure, and whose tips are pivoted to corresponding centering members 82, 84 and 86.
0, 112, 114, and each cylinder body 104,
Pipe 11 introducing compressed air into 106 and 108
6,118,120 and these pipes 116,1
Each cylinder body 104,1 via 18,120
06, 108 and a compressed air generation source (not shown). In addition, the mounting piece 100, the cylinder body 106, and the piston 1
12 is not shown for convenience of the drawing.

Although not shown in detail, the suction pump 30 described above includes a pressure detector for detecting a negative pressure state generated at the lower end opening of the suction pipe 24 in order to detect the suction force by the suction pipe 24. 122 is attached.

The operation of suctioning and transporting the optical lens 12 using the robot hand 10 configured as described above will be described below.

First, in a standby state for the transfer operation, the robot arm brings the robot hand 10 to the position indicated by reference numeral A in FIG. In this standby state, the centering members 82, 8
4, 86 are placed in a standby position just outside the corresponding regulating pieces 68, 70, 72, and the suction tube 24 is lifted upward, and each regulating piece 67, 70, 72 are each brought into a radially outwardly biased state.

From this standby state, when the robot is instructed by a control device (not shown) to aspirate a predetermined optical lens 12 and mount it in a lens barrel (not shown), the robot moves to the mounting stage B on which this optical lens 12 is placed. The robot arm is driven to move so that the robot hand 10 is located at the upper position. On the other hand, the second
The drive motor 80 starts and drives the threaded rod 54 to rotate around its own axis. In response to this rotation of the threaded rod 54, the slide block 66 moves along the radial direction of the hand body 14.

Here, the rotational driving force of the threaded rod 54 is generated by a bevel gear 60 coaxially fixed to the tip thereof and a bevel gear 18 rotatably attached to the hand body 14.
The rotation of the bevel gear 18 causes the bevel gears 56 and 58 that mesh with the bevel gear 18 to rotate together, thereby causing the threaded rods 50 and 52 to rotate. As the slide blocks 62 and 64 rotate, the other slide blocks 62 and 64 also rotate.
Similarly, it will move along the radial direction.

The amount of drive of the second drive motor 80, that is, the amount of movement of each slide block 62, 64, 66 is such that the lower end of each regulating piece 68, 70, 72 is at the outer periphery of the optical lens 12 to be sucked. The suction is applied so that the outer surface of each regulating piece 68, 70, 72 is positioned above the margin defined in the section, and more specifically, the outer surface of each regulating piece 68, 70, 72 is brought to a position aligned with the outer peripheral edge of this optical lens 12. optical lens 12
It is set according to the outer diameter dimension of.

When the robot hand 10 is brought above the optical lens 12 to be sucked, the robot arm is then lowered and the lower ends of the three regulating pieces 68, 70, 72 of the robot hand 10 are placed above the optical lens 12. Immediately before contacting the surface of 12, the downward movement is stopped. Thereafter, each air cylinder mechanism 90, 92, 94 is activated to rotationally drive the corresponding centering member 82, 84, 86 from the standby position to the centering position. As a result, even if the center position of the optical lens 12 at the mounting position is shifted from the center position of the hand body 14, the three centering members 82, 8
4 and 86 to the centering position, the hand body 14 is moved so as to be accurately aligned with the center position of the hand body 14, and a so-called centering operation is executed.

When the optical lens 12 is centered in this way, each regulation piece 68, 70, 72
It is located directly above the margin portion of the optical lens 12.

From this state, the suction pump 30 is activated and the suction operation by the suction tube 24 is started, and the first drive motor 74 is activated to rotationally drive the spur gear 16 to lower the suction tube 24. become.
In this way, the lower end opening of the suction tube 24 gradually approaches the center of the upper surface of the optical lens 12 (the portion including the optical function surface) from above. Meanwhile, the suction pressure (negative pressure) detection operation by the pressure detector 122 described above is started.

Here, as the suction tube 24 descends in this manner, the state of negative pressure generated at the lower end opening of the suction tube 24 gradually increases. and,
When the pressure detected by the pressure detector 122 reaches approximately 80% of the maximum vacuum pressure, the driving of the first drive motor 74 is stopped. Here, this maximum vacuum pressure is defined by the negative pressure generated when a suction operation is performed with the suction tube 24 in close contact with the optical lens 12. Then, at the point when the maximum vacuum pressure reaches about 80%,
The lower end of the suction tube 24 is set to be located slightly above the upper surface of the optical lens 12, as shown in FIG.

Specifically, in this embodiment, the maximum weight of the optical lens 12 is 100 g, and the maximum vacuum pressure is set to about 600 mmHg. Under these conditions, the 80% negative suction pressure is 480 mmHg, the gap between the suction tube 24 and the optical lens 12 is 0.03 mm when this negative suction pressure is achieved, and the suction force brought about by this negative suction pressure is Approximately 250g. Thus, in this embodiment, the suction tube 2
4 is not in contact with the optical lens 12, the optical lens 12 can be sucked and lifted by negative pressure.

In this way, the lower end of the suction tube 24 is connected to the optical lens 1.
The negative pressure generated when the optical lens 12 is located slightly above the top surface of the optical lens 12 is set to a value sufficient to urge the optical lens 12 upward.As a result, based on this negative pressure, the optical lens 12 , is urged from below by the lower ends of the three regulating pieces 68, 70, 72,
As shown in FIG. 4, the optical lens 12 is attracted and held by the robot hand 10.

The robot hand 10, which has attracted and held the optical lens 12 in this way, is transferred to a position above the location C where the lens barrel is placed as the robot arm moves in the vertical and lateral directions. At the time of such transfer, activation of each air cylinder mechanism 90, 92, 94 is stopped.
That is, the introduction of compressed air from a compressed air generation source (not shown) is stopped, and each piston 110, 112,
114 is the corresponding cylinder body 104, 106,
108. Due to this attraction,
Each centering member 82, 84, 86 is rotated from the centering position to an outward standby position.

In this way, the centering members 82, 84, 86
After the centering operation is canceled, the optical lens 12 is moved to a predetermined position within the lens barrel by the downward movement of the robot arm. Then, in a state where the optical lens 12 is moved to this predetermined position, the drive of the suction pump 30 is stopped, so that the optical lens 12 is moved to the robot hand 10.
The suction state of the lens is released, the lens is removed, and the lens is stored and held within the lens barrel.

Thereafter, the robot hand 10 is moved to the above-mentioned standby position and held there, thereby completing a type of movement of the optical lens 12.

As described in detail above, according to the robot hand 10 of this embodiment, the optical lens 12 as an article to be transferred is transferred while being sucked and held without contacting the optical functional surface. That's what I do. In particular, the regulating pieces 68, 70, 72 that contact the optical lens 12 are set so as to contact only the margin portion of the optical lens 12. In this way, the risk of damaging the optical functional surface of the optical lens 12 during this transfer is completely eliminated.

Further, according to the robot hand 10 of this embodiment, there is a member that holds the optical lens 12 inside the outer periphery of the optical lens 12 to be transported.
In this way, when the optical lens 12 is stored and held in the lens barrel,
This can be performed satisfactorily without impairing the holding operation.

It goes without saying that this invention is not limited to the configuration of the one embodiment described above, and can be modified in various ways without departing from the gist of this invention.

For example, in the embodiment described above, the case where the article is applied to the optical lens 12 has been described, but this invention is not limited to this, and can be applied to any article. This is effectively applied when the surface of an article has a functional surface that must not come into contact with it, and a margin portion that does not affect the function of the article in any way even if it comes into contact with it.

Further, in the above-mentioned embodiment, three regulating pieces are provided as shown by numerals 68, 70, and 72, but the number is not limited to this, and the number may be two or more. Any number of books is fine.

Furthermore, in the embodiment described above, the regulating piece 6
8, 70, and 72 are preliminarily determined according to the external dimensions of the optical lens 12 so that the outer surfaces of the optical lenses 8, 70, and 72
is moved vertically to align with the outer peripheral edge of the Therefore, the actual external dimensions of the optical lens 12 as an article to be transferred are
If it is larger than the set value, the centering members 82, 84, and 86 will ensure centering. However, if the actual external dimensions of the optical lens 12 are smaller than the set value, the centering members 82, 8
4 and 86, it will not be centered tightly, but will wobble by the amount that is smaller than the set value. In order to prevent such wobbling of the optical lens 12, as shown in FIGS. 5 and 6 as another embodiment, each centering member 8 is
A strain gauge 124 for measuring the contact pressure with the optical lens 12 may be provided at the portions of the lenses 2, 84, and 86 that contact the outer peripheral edge of the optical lens 12, respectively.

In this other embodiment, when the centering members 82, 84, 86 are performing the centering operation, each of the regulating pieces 68, 70, 72, as shown in the flowchart of FIG.
The second drive motor 80 is driven and controlled so that each outer surface and the outer peripheral edge of the optical lens 12 are precisely aligned in the vertical direction.

That is, in this control content, as shown in FIG. 2
The drive motor 80 is drive-controlled. Then, in step S2, each air cylinder mechanism 9
0, 92, 94 are activated, and each centering member 82, 84, 86 moves the corresponding regulating piece 68, 70,
It is rotationally driven so as to come into contact with the outer surface of 72.

Then, in step S3, the strain gauge 12
4, each centering member 82, 84, 8
6 and the optical lens 12 is detected. Based on this detection result, it is determined in step S4 whether or not this detection result, that is, the detected contact pressure has reached a target value.

If it is determined YES in this step S4, that is, if the detected contact pressure has reached the target value, the external dimensions of the optical lens 12 are exactly the same as the predetermined value, or , which is a large protrusion, and has been accurately centered by the centering operation executed in step S2, so the drive of the second drive motor 80 is stopped in step S5. In this way, a series of centering operation controls are completed.

On the other hand, if it is determined NO in step S4, that is, if the detected contact pressure has not reached the target value, the external dimensions of the optical lens 12 are smaller than the predetermined value. This means a state in which the centering members 82, 84, 86 are not in contact with the optical lens 12 with a predetermined contact pressure. In this case, since the outer surface of each regulating piece 68, 70, 72 protrudes radially outward from the outer peripheral edge of the optical lens 12, in step S6,
The second drive motor 80 is drive-controlled so that each regulating piece 68, 70, 72 moves radially inward.

As the second drive motor 80 is driven, each of the regulating pieces 68, 70, 72 moves inward in the radial direction, and along with this movement, each of the centering members 82, 84, 86 also moves inward in the radial direction and comes into contact with the outer peripheral edge of the optical lens 12,
This will ensure that it is centered without wobbling. Then, the control contents of step S3 and step S4 described above are executed, and the strain gauge 124
When the detected pressure reaches a predetermined value, as shown in step S5, the second drive motor 80
is stopped, and a series of centering control operations are completed.

According to the other embodiments, even if the outer dimensions of the optical lens 12 are smaller than a predetermined value, the optical lens 12 can be reliably centered without wobbling, and then It can be sucked and transported.

[Effects of the invention] As detailed above, the robot hand according to the invention is a robot hand for transferring an article having a functional surface portion and a non-functional margin portion on the upper surface, and is capable of vertical movement and side movement. A hand body is provided so as to be movable in the direction, and a plurality of hand bodies are attached to the hand body and have an outer surface that is vertically aligned with the outer periphery of the article to be transferred, and that abut the margin portion from above. A regulating piece is attached to the margin main body, and in a state where the regulating piece is in contact with the margin part of the article from above,
a suction member that is lowered to an upper position at a predetermined distance from approximately the center of the article; a centering position that contacts the outer surface of the hand body on the outer side of a corresponding regulation piece; It is characterized by comprising a plurality of centering members rotatably attached to a standby position spaced apart in the radial direction.

Therefore, according to this invention, there is provided a robot hand that can center an article, reliably suction it, and transport it to store it freely without directly contacting the functional surface of the article. It turns out.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the configuration of an embodiment of the robot hand according to this invention; Fig. 2 is a front view schematically showing the operating position of the robot hand shown in Fig. 1; A front view showing the state in which the suction tube approaches the margin part of the optical lens from above; Figure 4 shows the suction tube descending and approaching the optical lens, and this optical lens is sucked into contact with each regulation piece from below. A front view showing the state; FIG. 5 is a side view showing a centering member equipped with a strain gauge used in another embodiment of the robot hand according to this invention; and FIG. 3 is a flowchart showing details of drive control of the second drive motor. In the figure, 10... Robot hand, 12... Optical lens, 14... Hand body, 16... Spur gear,
18...Bevel gear, 20...Long groove, 22...Male thread portion, 24...Suction pipe, 26...Engagement pin, 28...
...Tube, 30...Suction pump, 32, 34,
36...Angle member, 38, 40, 42...Bending piece, 44a, 44b, 46a, 46b: 48
a, 48b...Guide rod, 50, 52, 54
... Threaded rod, 56, 58, 60 ... Bevel gear, 6
2, 64, 66...slide block, 68, 7
0, 72...Restriction piece, 74...First drive motor, 74a...Drive shaft, 76...Mounting stay,
78...Spur gear, 80...Second drive motor, 8
2, 84, 86...centering member, 88...
Pivot pin, 90, 92, 94... Air cylinder mechanism, 96... Pivot pin, 98, 100, 102
...Mounting piece, 104,106,108...Cylinder body, 110,112,114...Piston,
116, 118, 120...pipe, 122...
Pressure detector, 124... is a strain gauge.

Claims (1)

[Scope of Claim for Utility Model Registration] A robot hand for transporting an article having a functional surface portion and a non-functional margin portion on the upper surface, the hand body being provided to be movable vertically and laterally; a plurality of regulating pieces attached to the hand body, having outer surfaces vertically aligned with the outer periphery of the article to be transferred, and abutting the margin portion from above; In a state where the regulating piece is in contact with the margin portion of the article from above, a suction member is lowered to a position above the approximate center of the article at a predetermined distance, and the corresponding regulating piece is moved against the hand body. A robot characterized by having a plurality of centering members rotatably attached on the outside between a centering position abutting the outer surface of the robot and a standby position spaced radially outward from the centering position. hand.